Example embodiments relate to semiconductor memory devices, and more particularly, to stack array structures for semiconductor memory devices.
Semiconductor memory devices are generally classified as either volatile memory devices which lose stored data in the absence of applied power, or non-volatile memory devices which retain stored data when applied power is turned off or otherwise interrupted. The NAND flash memory device is widely used among the class of non-volatile memory devices. Generally, however, it is relatively difficult to increase the degree of integration of a NAND flash memory device. This is at least partly the result of channel length limitations of cell transistors and limitations relating to minimum sense currents in a NAND flash memory device.